Abstract: A rotating blade group 90 for a turbo-machine having an improved device for sealing the gap 110 between the edges 112,114 of adjacent blade platforms 96,104. The gap 110 between adjacent blades 92,100 is sealed by a seal pin 20 its central portion 110 and by a seal plate 58,60 at each of the front 54 and rear 56 portions. The seal plates 58,60 are inserted into corresponding grooves 62,64 formed in the adjacent edges 112,114 of adjoining blades 92,100 and held in place by end plates 40,42. The end of the seal plates 58,60 may be chamfered 78,80 to improve the seal against the end plate 40,42. The seal pin 20 provides the required damping between the blades 92,100 and the seal plates 58,60 provide improved sealing effectiveness.

Abstract: A damping member (27) for positioning between the undersides of the platforms of adjacent turbine blades (20) and the peripheral surface of a disc (19) upon which the turbine blades (20) are mounted. The damping member (27) comprises first, second and third portions (28,31 and 32). The first portion (28) simultaneously engages the adjacent blade platforms (24) whereas the second and third portions (31,32) converge to engage each other at the disc (19) peripheral surface from a spaced apart relationship with each other at their attachment to the first portion (28). Frictional interaction between the second and third portions (31,32) and the disc (19) peripheral surface provides damping of turbine blade (20) vibration.

Abstract: A rotatable assembly for use with a gas turbine engine comprises a rotatable disk, and a plurality of blades for affecting a flow of air passing thereover during use. The blades are attached to the rotatable disk, and each one of the plurality of blades has a blade root and a blade tip disposed opposite said blade root. A first ring self supporting is disposed adjacent a first portion of each of the blade tips, the first ring being in interfering contact with the first portion of each blade tip when the rotatable disk is stationary. The interfering contact is preferably between about 0.01 inches and about 0.1 inches. The first ring can be provided over a portion of the blade tips or can extend from about the leading edge of each blade to about its trailing edge. A second ring in interfering contact with the blade tips can also be provided.

Abstract: A method of applying a wear-resistant hardface material (alloy) to a portion of a turbine blade, typically a wear surface on a shrouded turbine blade. A thin foil of brazing alloy (which in the preferred embodiment is a nickel-based alloy) is placed over said wear surface, and a hardface alloy of a greater than desired thickness (which in the preferred embodiment is a cobalt-based alloy) is placed thereover, thereby sandwiching the foil therebetween. The wear surface, foil, and hardface material are heated for a period sufficient to melt the foil and cause bonding of the hardface alloy to the wear surface. The hardface material is thereafter machined to bring the wear surface to design tolerances. A turbine blade, and a method of rebuilding a portion of a turbine blade, are also disclosed.

Abstract: An air cleaner includes a housing having an upper wall and side walls, an air filter mounted with respect to the housing, a fan including a vane-wheel having a plurality of vanes, a supporting plate extending substantially between at least two side walls for supporting the fan. An air flow directional member directs an air flow output from the fan. The vane is formed to have a winglike cross-section, and the vane-wheel includes not more than four vanes. The vane-wheel has a base plate and a shroud. Each of the base plate and the shroud is formed to have a reinforcement portion on its circumference. A U-shaped balance weight is attached to a flattened portion formed on the curled portion. The air cleaner of the present invention can reduce noise and vibration and improve efficiency of the fan.

Abstract: An arrangement for attenuating vibrations of blades attached to a peripheral surface of a rotor of an axial turbine. A through hole is formed in each rotor blade in a generally thickness direction of the blade so that the through holes in combination define a single annular passage near a rotor surface when all of the rotor blades are attached to the rotor. A wire is provided to extend through the aligned through holes. Thus, the wire frictionally contacts the through holes when the blades are caused to vibrate due to a gas pressure and a centrifugal force generated upon operation of the axial turbine. Friction contact between the wire and the through holes attenuates vibrations of the blades.

Abstract: A rotor blade for a rotor of a gas turbine engine having an axis of rotation including a root portion, a platform portion connected to the root portion and having a damper pocket formed therein, an airfoil portion connected to the platform portion, a generally bar-shaped damping member loosely arranged in the damper pocket having at least one scrubbing surface, and at least one retainer pin for retaining the bar-shaped damping member in the damper pocket. The bar-shaped damping member is slidably displaceable and rotatable within the damper pocket during rotation of the rotor. The damper pocket in the platform portion has a rear surface with an upper portion and a lower portion at an angle to the upper portion, a pair of spaced side surfaces, and a pair of spaced lower surfaces extending from the rear surface lower portion which are substantially coplanar.

Abstract: A rotor blade for a rotor of a gas turbine engine having an axis of rotation including a root portion, a platform portion connected to the root portion and having a damper pocket formed therein, an airfoil portion connected to the platform portion, a generally bar-shaped damping member loosely arranged in the damper pocket having at least one scrubbing surface, and at least one leg extending from the bar-shaped damping member for retaining the bar-shaped damping member in the damper pocket. The bar-shaped damping member is slidably displaceable and rotatable within the damper pocket during rotation of the rotor. The damper pocket in the platform portion has a rear surface with an upper portion and a lower portion at an angle to the upper portion, a pair of spaced side surfaces, and a pair of spaced lower surfaces extending from the rear surface lower portion which are substantially coplanar.

Abstract: A damper for damping non-synchronous vibration in adjacent shrouded aerofoil blades is in the form of pin which locates in confronting passages in adjacent blade shrouds. The pin is provided with larger diameter portions which are located totally within the passages and frictionally engage the surfaces of the passages to provide vibration damping. The larger diameter pin portions are interconnected by a central, thinner portion. The configuration of the pin reduces the likelihood of it wearing in such a manner that it jams in the passages and no longer provides vibration damping.

Abstract: An aerodynamically optimized mid-span snubber for combustion turbine blades provides sufficient stiffness to ameliorate vibratory stress but does so with minimal degradation of aerodynamic performance. The snubber has an optimized aerodynamic cross-sectional shape that forms when two snubber portions attached to adjacent rotor blades come into contact upon rotation of the rotor at an operational velocity.

Abstract: The present turbine wheel assembly increases component life and turbine engine longevity. The combination of the strap and the opening combined with the preestablished area of the outer surface of the opening and the preestablished area of the outer circumferential surface of the strap and the friction between the strap and the opening increases the life and longevity of the turbine wheel assembly. Furthermore, the mass "M" or combined mass "CM" of the strap or straps and the centrifugal force assist in controlling vibrations and damping characteristics.

Abstract: A friction damper (50) provides friction damping for gas turbine engine airfoils to reduce vibrations thereto. The friction damper (50) includes a plate (52) underlying radially outer shrouds (30) of two adjacent airfoils (20). Friction generated between an outer surface (53) of the plate (52) and undersides (42) of the adjacent shrouds (30) reduces undesirable vibrations in the airfoils (20).

Abstract: A seal for sealing the gaps between adjacent turbine blade structures is disclosed in which the seal is disposed in a compartment formed between adjacent turbine blade structures having first and second sealing surfaces adjacent to a generally axially extending gap and a generally radially extending gap, respectively. The seal also has a thrust surface extending obliquely to a radius from the axis of rotation of the rotor disk to which the turbine blade structures are attached which is engaged with a reaction surface formed on a reaction member located in the compartment. During rotation of the rotor disk, centrifugal force acting in a radially outward direction is transmitted both radially and axially to a seal by contact between the reaction surface and the oblique thrust surface to cause the first sealing surface to seal the generally axially extending gap and the second sealing surface to seal the generally radially extending gap.

Abstract: An apparatus for sealing a gap between adjacent rotor blades of a turbine engine rotor assembly and for damping vibrations of the rotor blades is provided. The apparatus comprises a platform seal and a damping block. The damping block is independent of the platform seal and includes apparatus for coupling the platform seal and the damping block. The damping block selectively acts against adjacent rotor blades of the turbine engine rotor assembly, forward of the platform seal, and therefore does not interfere with the platform seal. The coupled damping block and platform seal may be installed in the rotor disc prior to installation of the adjacent rotor blades in the disc, thereby obviating the need to blindly install the platform seal.

Abstract: A blisk includes a disk and a plurality of inner airfoils extending radially outwardly therefrom, with each of the inner airfoils having an integral shroud support at a radially outer end thereof. A plurality of outer airfoils extend radially outwardly from respective ones of the shroud supports, and a plurality of discrete shroud segments are disposed respectively between adjacent ones of the shroud supports to collectively form an annular shroud for radially separating flow between the inner and outer airfoils. Each of the shroud segments is removably joined to only one of the adjacent shroud supports to improve manufacturing access, to allow replacability, and to allow differential movement and friction damping during operation.

Abstract: Vibration in the blade of a turbo-machine is suppressed by the incorporation of both inner and outer restraints that inhibit deflections of the blade foils. The outer restraint comprises shroud, welded lugs or tie wires that divide the row of blades into a plurality of blade groups by connecting the blades in each group together. The number of blades in each group can be equal to the number of blades in the row divided by the harmonic of the rotor rotational frequency that is closest to the blade resonant frequency of concern. The inner restraint comprises welded lugs or tie wires disposed radially inward from the outer restraint that divide each blade group into a plurality of sub-groups, thereby further suppressing blade vibration. Since the length of the inner restraints is less than that associated with harmonic shrouds, the stresses in the inner restraint, as well as in the blades, due to radial growth of the rotor are maintained within acceptable levels.

Abstract: A friction damper (50) provides friction damping for gas turbine engine airfoils to reduce vibrations therein. The friction damper (50) includes a plate (52) underlying radially outer shrouds (30) of two adjacent airfoils (20). Friction generated between an outer surface (53) of the plate (52) and undersides (42) of the adjacent shrouds (30) reduces undesirable vibrations in the airfoils (20).

Abstract: A turbine wheel and bucket assembly comprising a wheel having a peripheral rim machined to include a dovetail shape about the circumference of the rim, interrupted only by a bucket installation slot; and a plurality of buckets installed on the wheel, each bucket having a dovetail portion and blade portion, with the dovetail portion machined to include a complimentary dovetail shape enabling each bucket to be slidably received on the wheel dovetail shape; each bucket having an integral cover at a radial tip of the blade portion, each cover having axially extending surfaces on either side of angled contact surfaces adapted to engage mating contact surfaces of adjacent covers such that the buckets are pretwisted in a first direction. The dovetail shape includes a keyway and a complimentary key is provided on the rim of the wheel, the key receivable within the keyway to prevent rotation of the dovetail portion of the bucket relative to the wheel.

Abstract: The total number (M) of plural blades of a blade apparatus is selected so as not to be a prime number and not to be a power multiplier of a prime number. Plural blades are divided into at least a first blade group in which one blade group has the blades of a first integer number (N.sub.1) and a second blade group in which one blade group has blades of a second integer number (N.sub.2). Each of the first integer number (N.sub.1) and the second integer number (N.sub.2) have no common divisor except 1. The total number (M) of plural blades is the product of the first integer number (N.sub.1) and the second integer number (N.sub.2). The blades of the first integer number (N.sub.1) blade group are connected by a first stage connecting member and the blades of the second integer number (N.sub.2) blade group are connected by a second stage connecting member.

Abstract: A fluid propulsion device having blades and a surrounding frustroconical housing which rotates with the blades to accelerate fluid flow through the device. The device may be part of a marine drive or part of a fluid pump or motor.

Abstract: A rotor assembly 10 having a rotor disk 12 and a plurality of outwardly extending rotor blades 16 is disclosed. Various construction details are developed to provide effective cooling to the platform sections 20 of such rotor blades. In one particular embodiment, a damper 58 engages the underside of the rotor blades 16 and a seal member 42 inwardly of the damper engages the damper to provide damping of vibrations in the rotor blades. Both the damper and the seal member are provided with cooling air holes 42, 74 to positively distribute cooling air collected inwardly of the damper and seal member and to direct the cooling air preferentially between the adjacent platform sections 20 of the rotor blades to effectively cool the rotor blades.

Abstract: In a stabilizing device for extending the characteristic diagram of a compressor, which consists of a ring permanently attached to the impeller vanes of the impeller and a recess in the casing of the compressor in the form of a rotationally symmetrical groove, the ring is limited to the inlet region of the impeller and attached there in such a way that on rotation of the impeller, the ring can be moved in the recess, there being only a conventional close clearance between the ring and the wall of the casing. Due to this structure, the formation of a gap flow from the side of the vane at high pressure to that at low pressure is prevented, which leads to an increase in the efficiency of the compressor and to the widening of the compressor characteristic. The vibration loading on the vanes is lowered at the same time.

Abstract: A last-stage steam turbine bucket having a profile according to Charts I-XXXXI of Table I.The bucket is divided into a number of profile sections each of which is a predetermined radial distance from the root section. Each point on a profile section at the predetermined radial distance from the root is defined by an X-Y coordinate and a radius R along the arc of a circle connecting adjacent points.

Abstract: Turbine blades are held in groups formed by a series of spaced lugs constituting a lashing structure. Selected lugs have gaps which are "Z"-shaped, the gaps tending to close during untwisting of the blades when the blades are subjected to high centrifugal forces.

Abstract: A method of repairing a turbine blade comprising the steps of ascertaining a normal vibration characteristic of the blade, separating an outer end part of the blade from a residual inner part of the blade and subsequently securing a new end part to the residual part so that a joint between the new end part and the residual part is positioned in a predetermined relationship to said vibration characteristic.

Abstract: A shrouded aerofoil assembly such as a turbine rotor for a gas turbine engine has a multiplicity of blades with tip shrouds circumferentially distributed around a rotor disk. Inevitably, in use, the assembly vibrates and must be designed so the potentially most dangerous vibratory modes occur outside the engine speed range. The proposed arrangement has a number of neighbouring blades sharing a common shroud segment. Adjacent shroud segments are interlocked by Z-notch abutments. Blade assemblies have sufficient pre-twist load to maintain frictional contact in the interlocks over the speed range to maintain damping constraints.

Abstract: A rotor includes a disc having a plurality of blades extending therefrom. The blades include tip shrouds, each having first and second axial ends, and first and second circumferential faces. The first and second faces of adjacent tip shrouds are spaced from each other to define gaps therebetween. The first and second ends each include U-shaped slots, each having an arcuate damper wire disposed therein. The slots are aligned generally parallel to an axial centerline axis of the rotor for allowing ease of manufacture and assembly while providing effective frictional damping by the damper wires urged by centrifugal force against the slots.

Abstract: An integral shroud blade comprising a root portion for mounting the blade in a row on a turbine rotor; a platform portion; an airfoil portion extending upwardly from the platform portion and having a leading edge, a trailing edge, and a tip; a shroud formed on the tip of the airfoil portion and having two opposite tangential side surfaces and a top surface; and at least one pair of holes extending into the shroud, each of the two tangential sides having one hole of each pair being formed therein.

Abstract: A vibration damper is disposed between each adjacent pair of turbine buckets of a gas turbine engine to act in a V-shaped groove defined by bevelled platform surfaces of the adjacent buckets. The damper is wedge-shaped in cross section and is provided with a pad on one side and two pads on another side. When the damper is propelled into the groove by centrifugal force, it assumes a consistent equilibrium position with the raised surface of the one pad slidingly engaging one of the platform bevelled surfaces and the raised surfaces of the other two pads slidingly engaging the other bevelled platform surface to dissipate vibrational energy in the buckets.

Abstract: A shroud band for a rotor wheel having integral rotor blades wherein the shroud band has at least one Z-shaped separation gap at the band periphery, the Z-shaped gap having two parallel damping gaps which are axially spaced apart and which are inclined at an angle of from 70.degree. to 90.degree. relative to the axial direction. The damping gaps are narrow and are joined by an inclined wider free gap portion. During rotation, the damping gaps close up and the adjoining surfaces of the band come into frictional engagement whereas the free gap remains open.

Abstract: A fan for a turboshaft engine is disclosed comprising a rotatable disc having an array of blades secured at evenly spaced intervals around its periphery, each pair of successive blades and the disc defining a space which is delimited by the stem and a platform of a first of the two blades, the stem and a platform of the second of the two blades, and the periphery of the disc between the two blades.

Abstract: A lightweight, integrally bladed rotor has airfoils (18) and a full hoop blade platform (26), a support ring (28) is inside and spaced from the platform, with radial webs (30) extending from the support ring to the platform. Each web is a radial extension (32) of an airfoil. A radially extending shear plate (36) is secured to the platform and the ring.

Abstract: A method and apparatus for forming a hardened contact surface on a shroud of a turbomachinery blade comprising casting the blade and internal shroud with a metal insert into the casting mold so that the blade is cast with the insert in place. The insert may be formed with a projection extending from a wear surface of the shroud into the plane of the blade shroud such that the material from which the blade is made is cast about the projection to firmly and mechanically hold the insert in place. Each insert is preferably formed of a relatively low coefficient of friction and high wear resistant material whereby contact between abutting inserts on adjacent shroud surfaces have a high degree of slippage.

Abstract: An impeller for a centrifugal pump has a hub which is designed to be affixed to the pump shaft. The hub carries a first cover plate which is located at the pressure side of the impeller and supports a series of vanes defining flow channels. The first cover plate is secured to the bases of the vanes and a second cover plate situated at the suction side of the impeller abuts the tops of the vanes and overlies the flow channels. A suction port constituting an individually manufactured component is disposed at the inlet of the impeller and has a section of constant diameter which faces away from the vanes as well as a section of variable diameter which confronts the vanes. The section of variable diameter is connected to the tops of the vanes by a weld seam. The second cover plate overlies that end portion of the suction port having the greatest diameter and is secured to the tops of the vanes in an area between the suction port and the impeller outlet.

Abstract: The stator is made of ceramic matrix composite material and comprises: a bladed hub carrying blades with a radially projecting finger at the end of each blade; and two toothed rings having teeth facing one another with the rings being urged towards each other in order to hold each tenon of a blade both axially and circumferentially between a flank of one of the teeth of one of the rings and a flank of one of the teeth of the other ring. The rings are urged towards each other by resilient coupler which enables them to move apart from each other with the two rings also rotating relative to each other under the effect of the blade tenons expanding, with the stator being fixed to the casing of the turbojet by mechanical connections between the casing and one of the rings.

Abstract: A compressor impeller has a ring-shaped shroud band which is mounted at blade tips, each blade tip being enclosed in an identical radially slidable manner by a guide block, and the guide blocks being fastened to the shroud band. As a result, a narrow sealing gap and thus lower aerodynamic losses can be implemented than in conventional compressors, and the different centrifugally and thermally induced expansions of the blade and of the shroud band can be compensated.

Abstract: Disclosed is a vibration damped gas turbine engine airfoil row. The airfoil row, comprising first and second coaxial, circular spools and airfoils extending radially therebetween, is cast in at least one piece and then the second or inner spool is cut between adjacent airfoils. Damping inserts are held in place adjacent the inner surface of the second spool by a retaining means.

Abstract: A turbine aerofoil blade is provided with a shroud member at its radially outer extent for engagement with the corresponding shroud members of adjacent aerofoil blades. A cooling air duct within the shroud member directs cooling air to the abutment region of the shroud member so as to provide impingement cooling thereof. Ports provided in the cooling air duct direct a flow of cooling air from the duct over the outer surface of the abutment region so as to provide additional cooling thereof.

Abstract: A blade-to-blade vibration damper for a turbine rotor blade is disclosed. Each blade has airfoil, platform and root portions. A plurality of blades are circumferentially spaced about a rotor disk. An inclined recess extends into the platform portion of each blade from a first surface thereof, and toward its root portion. A U-shaped wire-form damping member has its in-turned marginal end portions slidably received in each recess. When the rotor disk is rotated at a sufficient angular speed, the damping members move outwardly by the centrifugal force acting thereon to engage the opposing surface of the platform portion of the adjacent blade. When so engaged, the members damp vibrations of such blades and seal the space between the opposing platform surfaces.

Abstract: An aerofoil balde rotor assembly in which a plurality of aerofoil blades having circumferentially extending platforms are located on the periphery of a rotatable disc. Each of the platforms is provided with tracks on its radially inner surface. The tracks of adjacent platforms define a convergent seating for a ceramic spherical damping member. Each spherical damping member frictionally engages the tracks of adjacent platforms simultaneously upon rotation of the assembly so as to provide aerofoil damping.

Abstract: An anti-rupture ring is slit axially at least at one location and is provided thereat with clamping devices which permit a rapid tightening and loosening of the anti-rupture ring. In one embodiment, the clamping of the anti-rupture ring can be varied hydraulically so as to minimize clearance losses in operation. The invention can be used in all types of turbo engines endangered by breakage of rotor blades, particularly in aircraft gas turbine construction, and it permits simple, damage-free mounting and a well-defined clamping of the anti-rupture ring.

Abstract: Blade platforms (26) for compressor blades with airfoils (22) in high solidity relationship have edges of a major portion (44) a minor portion (46), and a canted intermediate portion (48). Minimum clearance (54) exists between the major portions (44) whereby twisting during stackup or operation is avoided. A circumferential seal (60, 64) is located under the platform coincident with major portion (44).

Abstract: A gas turbine rotor blade platform sealing and damping system has elongated symmetrical insert elements of equilateral triangular cross-section loosely received within complementary shaped pockets at the spacing gaps between opposing convex and concave airfoil side edges of adjacently mounted blade platforms. The inserts and pockets are relatively configured to provide self-orientation of the inserts into gap sealing and vibration damping engagement with the platform edges when acted upon by centrifugal force due to rotor rotation. The convex platform edge is thickened at the point of closest proximity with the convex side of the airfoil. Alternative embodiments utilize insert grooves for increased leakage of cooling gas past the platform edges and incorporate a central bore for mass reduction.

Abstract: A ship's propulsion duct surrounding a propeller is constructed with a main body of glass-reinforced synthetic plastics material, and at least the throat of the duct is protected from the erosive mechanical effects of flow breakdown at the tips of the propeller blades by force-absorbing resilient material. The resilient material may be an inset ring of elastomer, or a lining of elastomer secured over the whole inner surface of the duct, or a resilient coating applied to the duct surface by painting.

Abstract: A power turbine (12) comprises alternate annular arrays of contra-rotatable turbine blades. Two arrays of turbine blades (30) and (47) have annular arrays of aerofoil propulsion blades (17,18) respectively attached thereto. Alternate arrays of turbine blades are attached to a primary drum member (55) in such a manner that below normal operating temperatures, limited relative radial movement is permitted between them. However when the normal operating temperature is reached, the relative radial movement is inhibited in such a manner that the rigidity of the power turbine (12) enhanced.

Abstract: In turbines, gaps arising between adjacent shrouds of integrally shrouded blades at high temperature are controlled or eliminated using pins inserted into opposing faces of shroud portions. These pins have a coefficient of thermal expansion greater than the integrally shrouded blade material and at least equal to that of the rotor material and, thus, protrude outwardly at operating temperatures. These protruding pins act to close the gap between shroud portions, thereby reducing vibration.

Abstract: A compressor blade assembly for a compressor operating at transonic or supersonic blade speeds has a part span shroud. The shroud is twisted having a first angle in the direction of airflow on one side of the shock wave and a second angle in the direction of airflow on the other side of the shock wave.

Abstract: An improved bladed rotor structure for an axial structure for a turbine which is easy to disassemble and produces high damping. Coupling members are located between adjacent blade ends to couple adjacent blades together. Anchoring elements affix adjacent blades with the coupling members which are non-rightangular parallelogram-shaped blocks.

Abstract: A steam turbine of the type employing axial entry, integral shroud blades has a pin disposed between adjacent shrouds that extends into tangentially oriented holes in the opposing faces of adjacent shrouds. The pins reduce blade flop during turning gear operation and reduce blade vibration during operation under load.

Abstract: An improved blade rotor structure for an axial flow turbine substantially reduces vibratory stress at resonant frequencies by rigidly connecting the blades to each other in groups equal in number to .[.an integer multiple of.]. the resonant frequency of the blades (i.e. a harmonic frequency) divided by .Iadd.an integer multiple of .Iaddend.the rotor running speed. Flexible tie means are used for connecting adjacent groups of blades together for substantially reducing axial-torsional vibration of the blades.